You can create amazing documents and presentations on your …
…로 멋진 문서와 프레젠테이션을 만들 수 있습니다.
‘presentations’ is a literal meaning and doesn’t fit in context since ‘프레젠테이션’ should come with 소개 (present/introduce) instead of 만들다 (make/create).

with iCloud
그리고 iCloud 덕분에
This phrase sounds awkward and would be redundant since the paragraph is under the subject ‘iCloud.’

you can keep that work up to date
최신 상태로 유지할 수 있습니다
유지 (keep) is a literal meaning. The rephrased term ‘update (업데이트할 수 있습니다)’ would be natural in context to deliver the equivalent IT term.

they automatically appear everywhere
모든 기기에서 자동으로 나타납니다
The structure follows English grammar. The verb 나타납니다 sounds awkward since the documents don’t appear by themselves. A passive verb form would be more appropriate in terms of sentence flow. To put it the other way, a functional term for ‘나타납니다 (appear)’ would be needed like 자동으로 표시됩니다 or 저장됩니다.

create a to-do list on your Mac
Mac에서 할 일 목록을 만들고
‘to-do list’ 할 일 목록 is not a common term and sounds awkward.

make edits to it on your iPhone
수정하는 일이 가능해집니다.
The structure follows English grammar. The proper wording would be 수정할 수 있습니다.

Start sketching on our iPod touch
iPod touch에서 스케치를 시작해
The transliterated term ‘스케치 (sketch)’ is ambiguous in context since it may imply a work-related frame.